Clutch Actuator Circuit Open
The P0900 code means the vehicle's onboard diagnostic system has detected: Clutch Actuator Circuit Open. This is a critical severity code.
- Keep driving?
- No — stop driving
- DIY difficulty
- hard
- Estimated cost
- $300 - $1,500 (parts and labor)
Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.
Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.
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Common Symptoms
- Check Engine Light illuminated
- Automated manual transmission will not engage or disengage clutch
- Vehicle will not move or stalls immediately
- Transmission stuck in neutral
Probable Causes (Ranked by Likelihood)
- Faulty clutch actuator motor Very High
- Open circuit in clutch actuator wiring High
- Disconnected connector at clutch actuator Moderate
- TCM output driver failure Low
Frequently Asked Questions
What is a clutch actuator?
In automated manual transmissions, the clutch actuator is an electric or hydraulic motor that engages and disengages the clutch automatically instead of a driver-operated pedal.
Can I drive at all with P0900?
No, if the clutch actuator circuit is open, the transmission cannot engage the clutch and the vehicle will not move. Have it towed to a repair facility.
Is this code specific to automated manual transmissions?
Yes, P0900 applies to vehicles with automated manual transmissions (AMT) or dual-clutch transmissions (DCT) that use an electrically or hydraulically controlled clutch actuator.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Check the clutch actuator connector is fully seated
-
Measure resistance at the clutch actuator motor terminals
-
Test for continuity in the wiring between the TCM and actuator
-
Command the clutch actuator with a bidirectional scan tool
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2011-2016 Ford Fiesta (PowerShift)
- 2012-2016 Ford Focus (PowerShift)
- 2010-2018 Fiat 500 (MTA)
- 2008-2016 Smart ForTwo
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